Brush holder for miniature electric motors



y 1, 1952 I 1 s. 1. BERGER 2,602,099

BRUSH HOLDER FOR MINIATURE ELECTRIC MOTOR Filed Sept. 20. 1949 NVENTO ATTORNEYS Patented July 1, 1 952 UNITED STATES PATENTOFFI E BRUSH HOLDER FOR MINIATURE ELECTRIC MOTORS Samuel 1. BeigenNewatk, N. J. a

Application'September 20, 1949, Serial No 116,826

. 10 Claims. (01. 171-324) 'It is among'the objects of the invention to proreadily assembled from inexpensive materialand which holder when once assembled is not likely to get loose or to jam or become out of order even after long use of the motor, and which will securely, yet resiliently hold the brush against the motor commutator without lateral play in the brushes and thus avoids uneven wearing or sparking. 1

According to the invention'these objects are accomplished by the arrangement and combination of elements hereinafter describedand particularly recited in the claims.

In the accompanying" drawings in which is shown one or more of various possible embodiments of the several features of the invention,

Fig. l is a fragmentary side elevational view of a motor showing the brush holder in its relation to the armature and the commutator,

Fig. 2 is a view partly in cross section taken along line 2--2 of Fig. I,

Fig. 3 is a view of the brush holder taken along line 3-3 ofFig. 1, v I

Fig. 4 is a longitudinal sectional view on a larger scale, taken along line 4-4 of Fig. 2, i

Fig. 5 is a transverse sectional view taken along line 55 of Fig. 2, a

Fig. 6 is a perspective view on a larger scale of one of the brush mounts, and

Fig. 7 is a view similar to Fig. 6 of another embodiment of the brush mount.

Referring now to the drawings, the motor includes a shaft I carrying the usual armature I2 and commutator l3. Associated with the com mutator and desirably mounted on the motor frame (not shown) is a brush holder M which desirably comprises a plate l5 of insulating material having a bearing l-B therein through which an end ll of the shaft I I extends.

The plate |5 carries a pair of brush mounts I8 and I9 which preferably are identical and which support the brushes'2| and 22 respectively which engage'the commutator I3.

As shown in Fig. 6,.each brush mount comprises a strip of conducting material preferably of copper; reversely bent as at 23 and conformed at such reversely bent portion to provide substantially a cylindrical socket 24 for the brush rod.

The. strip is preferably of reduced width from the socket 24 to the free ends 25 thereof so that the end 26 of the socket protrudes at rightlangles beyond the edges-flof'the legs .28 of ,thebrush 2 mount, and each of said legs 28 has .a tab 29 formed integral with each edge 21 thereof. The free ends 25 of the strip are desirably bent towards each-other and preferably are in abutment so as to retainthe legs 28 in parallel relation. An ear 3| is desirably struck out from the wall of one of the legs 28 and extends laterally therefrom into a preferably smaller opening 32 formed in the wall of the other leg 28.

In the embodiment of the brush mount shown in Fig. 7 which is substantially identical to the brush mount shown in Fig. 6, the parts corresponding to those of Fig. 6 have the same reference numerals primed.

The free end 4| of one of the legs 28' of the brush mount of Fig. 7, is inwardly bent at right angle so as to abut against the other leg '28 to retain the legs 28' inparallel relation, the end 42 of such latterv leg 28 extending beyond the end 4| and preferablyzbeing provided with an opening 43 to facilitate. connection of a lead 43 thereto.

Thebrush' mounts l8 and I!) are positioned on the plate |5 with, the protruding end 26 of socket 24 extending through an opening 33 in the plate l5 and lying flush with a face 35 thereof and with the edges 21 of the legs 28 resting against the other face 36 of the plate IS. The tabs 29 extend respectively through a pair of openings 31 in the plate and are bent over, as shown in Fig. 3, securelyto retain the mounts on the plate.

Each of the brushes which is positionedin an associated socket, isof diameter slightly smaller than'such socket so that it may slide therein and is resiliently retained against the commutator I3 by a tensed coilspring 38 which encompasses ear 3|, the spring having an extending end '39 which presses against the end of the brush and an extending end 4| which rests on the face {it of the plate to retain the spring in tensed condition.

By reason of the above described construction as the ear 3| is formed integral with the wall of a leg 28 of the mount, it will not loosen under vibration or be lost even with continuous operationof the motor.

Inasmuch as the end of the ear extends through an opening 32 in the opposed leg 28, the ear will: not bend from its substantially right angle position and hence will not compress or move the spring, so that jamming thereof is avoided.

- Also by reason of the inwardly bent ends 25 of the legs 28 of the mount shown in Fig. 6 and the inwardly bent end 4| of one of the legs 28 of the mount shown in Fig. 7, the legs will be retained in substantially parallel spaced relation and hence will not come together so that binding of the spring will not occur.

As many changes could be made in the above construction, and many apparently widely different embodiments of this invention could be made Without departing from the scope of the claims, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, whatl claim as new and desire to secure by Letter's'Pate ent of the United States is:

1. In an electric motor of the type com-prising a shaft; an armature and a commutator. mounted on said shaft, the combination therewith of a brush holder comprising a plate of insulatingmaterial, a brush mount aflixed to said plate comprising a strip of conducting material havinga socket portion at one end thereof slidably mount ing such brush, said socket portionhaying one end thereof. protruding beyond the associated edgeof said strip and said plate. havingan opening therein to receive the protruding end of said socket portion, an ear rigid. with said strip and extending laterally therefrom, and a tensed coil spring encompassing saidear and having one end thereof extending into said socket normally urging such brush out o-fsaid socket against said commutator.

2. The combination set forth in claim l in which the means afiixing said mount-t0 said plate comprises a tab-formed integrally with said edge of said strip and extending through an opening in said plate.

3. In an electric motor of the type comprising a shaft, an armature and a commutator mounted on said shaft; the. combination therewith of a brush holder comprising a plate of insulating material, a brush mount comprising a reversely bent strip of conducting material having apair of.

spaced legs and having a socket portion. .at the reversely bent end thereof: to mount such brush, said socket having one. end thereof protruding beyond the associated'edg'es of said legs and said plate having an opening therein to; receive. the protruding end of said socket, said legs each having a tab formed integral with each of said associated edges thereof and extending through an opening in said plate, whereby when said tabs are bent over, said mount will be securelyaifixedto said'plate, one of said legs having an .ear struck out therefrom and extending laterallytoward the other-of said legs, said last named leg having an opening therein to receive the end of said car, a tensed coil spring encompassing said earand having one end thereofextending into said socket and normally urging such brush out of said socket against said commutator, the free end of. said legs being inwardly bent toward each other andin abutment thereby to retain said legs in parallel relation.

4. As an article of manufacture,-a brush holder comprising a reversely bent strip of conducting material having a pair of spaced legs and having a socket portion at the reversely bent end thereof, socket protruding beyond the associated edges of said legs, one of saidlegs having. an ear struck out therefrom and extending laterally into an opening in the other of said legs, said legs each having atab formed integral with the edge thereofassociated with the-protruding portion of said socket. a

5. As an article of manufacture, a brush holder comprising a reversely bent strip of conducting material having a pair of spaced legs and having a socket portion at the reversely bent end thereof, said socket protruding beyond the associated edges of said legs, one of said legs having an ear struck out therefrom and extending laterally into an opening in the other of said legs, said legs each having, a tab formed integral with the edge thereof associated with the protruding portion of said socket, the free ends of said legs being inwardly bent toward each other and in abutment, thereby to retain said legs in spaced relation.

6; As an article of manufacture, a brush holder comprising a reversely bent strip of conducting material having a pair of spaced legs and having av socket. portion at the reversely bent end thereof, said socket protruding beyond the associated edges of said legs, one of said legs having an ear struck out therefrom and extending laterally into an opening in the other of said legs, said legs each having a tab formed integral with the. edge thereof associated with the protruding portion of said socket; the freeend of one of said legs being inwardl-ybent at right angles to abut against the other of said legs, the free end of said last named leg extendingbeyond the inwardly bent end of said firstnamed leg.

'7'. In an electric motor of the type comprising a shaft, an armature and a commutator mounted on said shaft; the combination therewith of a brush holder comprising a plate of insulating material, a. brush mountaffixed to said plate comprising a strip'of conducting material having a tab formed integrally with the'edge thereof, said plate having an aperture through which said tab extends, said strip having a socket portion at one end thereof slidably mounting such brush, said socket portion having one end thereof protruding beyond the associated edge'of said strip and said plate having an opening therein to receive the protruding end of said socket, an ear rigid with said strip and extending laterally therefrom, and a tensed coil spring encompassing said ear and having one end thereof extending into said socket portion normally urging such brush out of said socket portion against said commutator.

8. In an electric motor of thetype comprising a. shaft, an armature and a commutator mounted on said shaft; the combination therewith of a brush holder comprising a plate of insulating material, a brush mount afiixed to said plate comprisinga reversely bent strip of conducting material having a pair of'spaced legs and having a socket portion .atthe reversely bent end thereof slidablytoamountsuch brush, one of said legs having an ear struck out therefrom and extendingalaterallytoward the other of said legs, said last named leghavingpan' opening therein into which said ear extends, thereby to prevent lateral displacement. of said ear, and a tensed coil spring encompassing said 1 ear and having one end thereof extending into said socket portion and normallyurgingjsuchbrush out of said socket portion againstsaid commutator.

9..In an electric motor of the type comprising a. shaft,.an armature and acommutator mounted on said shaft; the combination therewith of a brush holder comprising a plate of insulating material, abrush mount affixed to said plate comprising a reversely bentstrip of conducting material having a:pair of spaced legs and having a socketportionv at the. reverselybent end thereof slidably to mountsuch brush, one of said legs h'aving'an ear struckout therefrom and extending laterally toward the other of said legs, the

each other and being in abutment, thereby to retain said legs in spaced parallel relation, and a tensed coil spring encompassing saidearand having one end thereof extending into said socket portion and normally urging such brush out of said socket portion against said commutator.

10. In an electric motor of the type comprising a shaft, an armature and a commutator mounted on said shaft; the combination therewith of a brush holder comprising a plate of insulating material, a brush mount aflixed to said plate comprising a reversely bent strip of conducting material having a pair of spaced legs and having a socket portion at the reversely bent end thereof slidably to mount such brush, one of said legs having an ear struck out therefrom and extending laterally toward the other of said legs, the free end of one of said legs being inwardly bent at right angles to abut against the other of said legs, the free end of said last named leg extending beyond the inwardly bent end of said first named leg, and atensed coil spring encompassing said ear and having, one end thereof extending into said socket portion and normally urging such brush out of said socket portion against said commutator.

SAMUEL I. BERGER.

REFERENCES CITED The following references areof record in the file of this patent:

UNITED STATES PATENTS Edmundson Dec. 3, 1946 

